During neural development, cellular differentiation of precursor cells generate a precise pattern within the embryo that is required for proper function. Cells are specified by receiving a series of inductive signals from the environment or within the cell itself, that instructs the cell toward a specific program of differentiation. A model system for studying the molecular events of neural development in the embryonic zebrafish. Due to the ability to perform large scale genetic screens, anamniotic mode of development, [d generation time and optical lucidity offers ideal conditions to study events in early embryogenesis invertebrates. The process of dorsal neural tube and neural crest formation and migration is a ideal system studying Patterning events during neural development. The specific goal of this proposal is to identify characterize genetic mutants that have specific defects in the dorsal neural tube. To this end, a large e genetic screen will be initiated to specifically screen using a battery of molecular probes, for dorsal neural tube mutants. Once these mutants are identified, it is the long term goal of this proposal to initiate cloning strategies and embryological techniques to determine the role of these genetic loci during development.